1. Field of the Invention
The present invention relates to a probe including a plurality of optical fibers of which at least leading end portions are arranged in parallel with each other and an optical member of which a base end face is arranged to abut on leading end faces the optical fibers, and a leading end face is exposed externally.
2. Description of the Related Art
In recent years, there is known a measurement method for measuring an optical characteristic of body tissue while a probe leading end directly makes contact with body tissue by inserting a probe into a forceps channel of an endoscope for observing internal organs such as digestive organs and protruding the probe leading end from the endoscope.
For example, there has been proposed an optical measurement apparatus using low-coherence enhanced backscattering (LEBS) technique for detecting properties of body tissue by irradiating low-coherent white light having a short spatial coherent length from an irradiation fiber leading end of a probe onto body tissue and measuring an intensity distribution of scattering light beams having a plurality angles using a plurality of light-receiving fibers (for example, refer to International Patent Publication Pamphlet No. W02007/133684 or U.S. Patent Application Laid-Open No. 2008/0037024). In such an optical measurement apparatus, a transparent rod is provided in the probe leading end, and a distance between leading end faces of respective fibers and body tissue as a measurement target is regularized to obtain stability of measurement (for example, refer to Japanese Laid-open Patent Publication No. 2002-535027). In addition, in the probe disclosed in Japanese Laid-open. Patent Publication No. 2002-535027, in order to prevent undesired light, which is reflected by the leading end face of the rod without reaching the body tissue, from reaching the light-receiving fiber, the leading end face of the rod is notched with an inclination relative to the longitudinal direction of the probe so that only the scattering light of the obtainment target is measured.